Lighting control system



NOV. 21, 1939. C w ss I 2,180,764

LIGHTING CONTROL SYSTEM Filed March 9, 1936 7 Sheets-Sheet 1 WHlTELiGHTS 4-8 BLUE UGHTS WHITE LlGHTS Clarence WA/esseZZ By A a M Nov. 21,1939. c. w. NESSELL LIGHTING CONTROL SYSTEM Filed March 9, 1936 7Sheets-Sheet 2 NO. BORDER NO- '2 BORDER T0 OT HER CONTROLS TO OTHERMOTORS OZaf'ence WA/ssell NONE NTA Y FOOTS M i a H GREEN PLOT .FUWMWE w02 khmmmmn. OZ FMWMEQ N 02 Nov. 21, 1939. c. w. NESSELL 2,180,764

LIGHTING CONTROL SYSTEM Filed March 9, 1936 7 Sheets-Sheet 3 FOOTS OTHERMOTORS NO. BORDER NO-Z BORDER GREEN Pl LOT 426 v MOMENTARY swwcu 3 Fig.5

Clarence W NesseZZ Nov. 21, 1939. c. w. NESSELL LIGHTING CONTROL SYSTEMFiled March 9, 1936 7 Sheets-Sheet 4 Inventor CZarerzae WNess'eZ Z MMmm; MN; MM MM E $2 om mm mm mm mm mmzmu mu m 10.52% @0 60 72% MwQdOm Nm2 MmcMOm mZ WPOOL zukim 10 60 m; M

Nov. 21, 1939. c. w. NESSELL LIGHTING CONTROL SYSTEM Eiled March 9, 19367 Sheets-Sheet 6 WHITE STAGE REH E-P-RSAL SWITCH 2'22;

Gum/MA;

N2 I BORDER 8 1 Clafiemce WNBSSHZZ Nov. 21, 1939. c. w. NESSELL LIGHTINGCONTROL SYSTEM Filed March 9, 1936 7 Sheets-Sheet 7 H 4 7 6 V a M WW l-00 w w O 3 N L R ll oo T w m w 5 in m H w W S m G E M 5 a U L L e 0 2| mm m C N & 5 P P P W 0H. 0 S S S o 2 M o. 3 b. 6 E51 w Rs 5 5 w V w B B I0 a 1 m 5 I I 2 m m 7 7 M 1P B R W m U U 5 m 1 m i w E w L2 5 2 5 m m I1 R E N s M W m m m m a B B A A 2 A R w B m E a w E R BRw 1 R W B W 47)? B F i 5 NO. '2 PRESET fhtoMw/q NO. 1 PRE SET Patented Nov. 21, 1939UNITED STATES mats LIGHTING oom'mor.- srs'rsu Clarence W. Ncssell,Forest Park, Ill, assignor to Minneapolis-Honeywell Regulator Company,Minneapolis, Minn, a corporation of Delaware Application March 9, 1938,Serial No. 87,819

38 Claims.

This invention relates to lighting control systems in general and moreparticularly to lighting control systems for use in theatres,auditoriums and the like.

Present day theatres are equipped with various groups of lights forobtaining diiierent lighting eilects on the stage and in the auditoriumproper. These groups of lights usually comprise iootlights, borderlights, flood lights and spotlights for the stage, and domej lights,wall lights and alcove lights for the auditorium. Each group isgenerally provided with a plurality of variously colored lights.Thevarious lights the various groups are usually controlled by means ofordinary resistance type dimmer plates or by means of the more recentcore type reactors where the lighting load is relatively great.

Attemptshave been made in the past to remotely control the variouslights of the various 20 groups bu these attempts have not been entirelysuccessful.

It is therefore the prime object 01 this invention to control thevarious lights oi. the various groups in a new and novel manner wherebyinnumerable combinations bi colors and intensities of lights may beobtained and accurately controlled.

' In carrying out my invention I contemplate locating the resistancetype dimmer plates or the core type reactors adjacent the lights theycont'rol, operating these resistance type dimmer plates or core typereactors by 'power means which may. take the form of proportioningmotors operatively connected thereto, and controlling these power meansby control devices which may take the form oisuitable switches andcontrol impedances located on one or more conveniently located panelboards.

An object of this invention is to provide a control system forcontrolling the intensities or colors of lights comprising, aproportioning motor -operable to a plurality of positions, and aremotely located control device which may take the form oi an adjustablepotentiometer ior po-. sitioning the proportioning motor whereby theintensities or colors of lights may be accurately controlled.

Another object oi this invention is to provide a controlsystem forcontrolling the intensities or colors of lights comprising aproportioning motor operable to a plurality of positions, a controlpotentimeter for positioning the proportioning motor in any desiredposition, and switching means for rendering the control potentiometer5&5, ineflective to control the proportioning motor moved to a newposition corresponding to the newly adjusted position of the controlpotentiometer upon subsequent operation of the switchin means.

Still anotherobiect of this invention is to provide a control system forcontrolling the intensities or colors of lights comprising aproportioning motor operable to a plurality of positions, a plurality ofcontrol potentiometers for the proportioning motor, and switching meansfor selectively transferring the control of the proportioning motor fromone potentiometer to another.

A further object of this invention is to provide "a control system forcontrolling the intensities or colors'oi lights comprising a pluralityoi proportioning motors and a singlecontrol potentiometer for themotorswhereby the motors all assume positions corresponding'to theadjustment of the control potentiometer.

Still a further object of this invention is to provide a control systemfor controlling the intensities or colors of lights comprising aplurality of proportioning motors, a control potentiometer for eachmotor for positioning the same, another control potentiometer Ior all ofthe motors for similarly positioning all of the motors, and meansiortransterringthe control of the motors from their respective controlpotentiometers to the single control potentiometer.

Another object of this invention is to provide a plurality of motorsthat are movable to given positions to controlthe intensities and colorcom- 1 binations of lights with means for proportionately operating themotors to proportionately dim or brighten the lights whereby the lightsmay be extinguished or brightened to full intensity simultaneouslyregardless of the intensities of the lights before this operation takesplace.

A further object of this invention is to provide a plurality ofproportioning motors, an adjustable control potentiometer ior each motorfor pcsitioning each motor in accordance with the adiustment of itscontrol potentiometer, and other potentiometers for the motors tooperate the motors to an extreme position in such a manner that eachmotor arrives at the extreme position at substantially the same timeregardless of the position it was in prior to that time.

Still another object oithis invention is to provide a plurality orcontrol devices for lighting control system arranged in presets alongwith means for automatically rendering the preset in control inoperativewhen another preset is placed in operation.

A further object of this invention is to provide a control system forlights wherein the intensities of the lights and color combinationsthereof may be selected and controlled at will and wherein the lightsmay all be extinguished by the manipulation of a blackout switchincluded in the control system.

A'still further object of this invention is to provied a plurality ofcontrol stations for a-lighting control system wherein the lightintensities and color combinations of the lights may be manipulated fromany convenient location.

' Another object of this invention is to provide a plurality of controlstations for lighting control systems along with interlocking means forpreventing the control of the lighting system by more than one stationat any one time.

Another object of this invention is to provide individual or groupcontrol of light intensities or color combinations irrespective of anypresets which finds particular utility during rehearsals or whenimmediate light changes are desired.

Still another object ofthis invention is to provide a proportioningmotor for positioning a color wheel of a spotlight in any one of anumber of positions, the proportioning motor being controlled byremotely located control devices.

Other objects of this invention reside in the combination of the variousnovel features of this invention into complete and novel control systemsnever before contemplated.

Further objects and advantages of this invention will become apparent tothose skilled in the art upon reference to the accompanyingspecification, claims and drawings, in which drawmgs:

Figure 1 diagrammatically illustrates the basic principles'of operationof the control system of this invention, various combinations of whichare disclosed in the remaining figures;

Figures 2 and 3 when placed side by side diagrammatically illustrate oneform of this invention wherein a plurality of interlocked presets and aplurality of interlocked control stations are provided;

Figure 4 diagrammatically illustrates another form of this inventionwherein the control devices are arranged in groups, wherein the controldevices of each group or all of the groups may be preset, and whereinall of the lights may be simultaneously extinguished as by means of ablackout switch;

Figure 5 diagrammatically illustrates another form of this inventionwherein the control devices are arranged in groups, wherein the controldevices of each group or all of the groups may be preset, wherein thelights of each group may be controlled by a master control device andwherein all of the lights may be controlled by a stage master controldevice or a remotely located control device;

Figure 6 diagrammatically illustrates another formof my inventionwherein the control devices are arranged in presets, wherein othercontrol devices are arranged for trying light combina tions irrespectiveof any preset and wherein the lights may be proportionately dimmed orbrightened; and

Figure 7 diagrammatically illustrates my invention as applied to thecontrol of a color wheel of a spotlight. 4

Figure 1 Referring now to Figure l, I have disclosed the basic portionof my control system, combinations of which are shown in the remainingfigures. For purposes of illustration I have shown diagrammaticallyresistance type dimmer plates generally designated at I0 for controllinga lamp load in the form of lights generally designated at II. The lamploads II at the left of Figure 1 are designated white lights, and thoseat the right of Figure 1 are designated blue lights. It is within thecontemplation of this invention also to vary the lamp loads H by anyother means known in the art such as core type reactors equipped withchoke coils having D. C. fields, the choking effect of which may begoverned by potentiometer type resistance dimmer plates instead of theresistance dimmer plates I0 disclosed or by reactors in which the coreis rotated.' These latter types of control of the lighting loads areusually used for lighting loads of over 10,000 watts, but for purposesof illustration the simplest type is shown in Figure l. The resistancetype dimmer plates or the potentiometer type resistance plates for usewithin core type reactors or the cores themselves may be operated byproportioning motors generally designated at I2. The proportioningmotors I2 may in turn be positioned in any number of a plurality ofpositions by means of control potentiometers generally designated at I3.Fader potentiometers are designated at I4 for also controlling theproportioning motors I2 whereby the proportioning motors I2 may beproportionately moved to off or on positions in a specific manner to bepointed out more fully hereafter. The control potentiometer I3 at theleft of Figure 1 controls the white lights II and the controlpotentiometer I3 at the right of Figure 1 controls the blue lights IIand therefore like reference characters have been utilized throughout.

The dimmer plates I0 and the proportioning motors I2 are preferablylocated adjacent the lamp loads II and the proportioning motors I2 aremechanically connected to the dimmer plates I0. The controlpotentiometers I3 for controlling the proportioning motors I2 may belocated on a panel board located in some convenient place remote fromthe proportioning motors I2 and the dimmer plates I0. The'faderpotentiometers I4 maybe located if desired on the same panel board withthe control potentiometers I3.

Line wires leading from some source of power, not shown, are designatedat I5 and IS. The line wire I6 may be connected by a wire I I to one endof the resistance I8 of the dimmer plate I0. A slider I9 cooperatingwith the resistance I8 is connected by a switch 20 and a wire 2| to thelights II forming the lamp load. The lights II are in turn connected bya wire 22 to the other line wire Iii The lights II are located inparallel and the resistance I8 is located in series with the lights.Itis therefore seen that as the slider I8 is moved in acounter-clockwise direction the light intensities of the lamps II areincreased and when the slider I9 is moved in a clockwise switch 20 whenall of the resistance I8 is placed. 75

to the balancing potentiometer coil 33.

is adapted to open the switch 33 to interrupt the supply of current tothe lights The light intensities of the lamps II are thus .adiusted andwhen they are dimmed tow a predetermined intensity they may beextinguished.

The sliders l3 may be rotated tioning motors I3 through the medium or ashaft 35 which may be driven through suitable gearing 33 by a motorshaft 31. The motor shaft 31 is in turn rotated through reductiongearing 33 by motor rotors 33 and 33 upon energization of field windings3|, and 33. The shaft 31 also rotates a slider 33 with respect to abalancingv potentiometer coil 33. The arrangement is such that when thefield winding 3| is energized the slider 13 associated'with theresistance I3 is rotated in a clockwise direction to dim the lights IIand the slider 33 is rotated to the left with respect the field winding33 is energized the slider I3 is moved in a counter-clockwise directionwith respect to the resistance l3 to brighten the lamps II, and theslider 33 is moved to the right with respect to thebalanclngpotentiometer coil-33.

Proportioning motor i3 also includes a relay comprising coils 35 and 33for operating a core 31 which is suitably connected to a switch arm 33.The switch arm 33 is adapted to cooperate with spaced contacts 33- and33. -When the relay coil 35 is energized more than the relay coil 33,switch arm 33 is moved into engagement with the contact 33 and when therelay coil 33 is energized more than the relay coil 35 the switch arm 33is moved into engagement with the contact 33. When the relay coils 35'and 33 are equally energized or when they are deenergized the switch arm33 is maintained in aposition midway between the contacts 33 and 33 asshown in the drawing. For a'iurther detailed understanding oi theproportioning motor l3 reference is made to application Serial No.673,236 filed by Lewis L. Cunningham on .May 2'1, 1933,- now Patent No.2,180,400 of May. 30, 1939.

The contact 33 is connected by wire 3| to one end oi the field winding3| and likewise the contact 33 is connected by a wire 33 to one end ofthe field winding 33. The switch arm 33 is connected by wires "and 33 tothe line wire l5, and the junction of the field windings 3| and 33 isconnected by wires 35 and 33 to the other line wire l5. When the switcharm 33 is moved into engagement with the contact 33, a circuit iscompleted from the line wire l5 through wires 33 and 33, switch arm 33,contact 33, wire 3|, field winding 3| and wires 35 and 33 back totheother line wire l3. Completion of this circuit causes energizationoi' '-the field winding 3| to dim the lights II in the manner pointedout above. Movement 01 the switch arm 33 into engagementwith the contact33 completesa circuit from the line wire l5 through wires 33 and 33,switch arm 33, contact 33, wire 33, field winding 33 and wires 35 and 33back to'the other line wire l3. Completion of this circuitcausesenergiaation oi the field. winding 33 to cause brightening of the lightsll. When the switch arm :33 is in the midposition shown in the drawing,neither field winding 3| or 33 is energized and the slider i3 ismaintained in a given position to maintain the light intensities of thelamps I at the adjusted value. Suitable limit switches,

not shown, may be provided in the wires 31 and 33 to prev'ent'overtraveloi the proportioning moby the propor- When end of the potentiometer coilcoil 33 is connected by the center of tor I3 and consequent overtrave loi the slider l3 with respect to the resistance l3.

. The control potentiometer generally designat ed at l3 may comprise apotentiometer coil 31 and a manually operated slider 33 cooperatingtherewith. Suitable indications may be associated with the slider 33 toindicate the light intensities which the lamps II will assume when theslider coincides with certain of the indications. The iaderpotentiometers i3 may comprise potentiometer coils 33 and sliders 53cooperating therewith. Preferably the sliders 53 are mounted on a commonshaft 5| whereby the sliders 53 of both Iader potentiometers H aresimultaneously rotated. The shaft 5| is shown to be operated by a knob53, although the shaft 5|. may be operated in any suitable manner suchas by a timing motor or by a remotely controlled motor similar toproportioning motor l3.

The primary 53 of having a secondary 55 is connected across the linewires l5 and I5. The secondary 55 is connected to a double pole singlethrow switch 53. One of the poles of switch 53 is connected by awire--51 to one end or the relay coil 35. 'The other pole of the switch55 is connected by a wire 53 to one end of the relay coil 35. Thelife-hand end of the potentiometer coil 31 of the control potentiometeri3 is connected by wire 53 tothe wire 51, and likewise the right-hand 31is connected by 53. The left-handend of the potentiometer coil 33 of theiader potentiometer i3 is connected'by wire 3| to the wire 51 andlikewise the right-hand end of the potentiometer wire 53 to the wire 53.The left-hand end of the balancing potentiometer coil 33 is connected byto the left-hand end of wire 53 to the wire the relay coil 35 andlikewise the right-hand end of the balancing potentiometer coil 33 isconnected by a protective resistance 53 to the right-hand end of therelay coil 33. In this manner it is seen that the potentiometer coils 31of the control potentiometer I3, 33 of the fader potentiometer I3; and33 of the balancing potentiometer and the relay coils 35 and 33, are allconnected in parallel and across the secondary 55 of the step-downtransformer 53 when the double pole single throw switch 53 is closed.The slider 33-01 the control potentiometer i3 is connected by a wire 55to the potentiometer coil 33 of the iader potentiometer l3. The slider53 of the iader potentiometer I3 is connected by a wire 66, a switch 31,a wire 53 and'a resistance 53 to the Junction of the relaycoils 35 and33. The junction of the relay coils 35 and 33 is also connected by awire 13 to the slider 33 associated with the balancing potentiometercoil 33. When the switch 31, which may be manually operated, is closedand when the slider 53 oil the fader p0- tentiometer i3 is in themidposition, the slider a step-down transformer 53 a protectiveresistance 33 33 of the control potentiometer l3, the slider V 33 of thebalancing potentiometer, and the junction of the relay coils 35 and 33are connected together.

Referring now to the upper left-hand portion oi. Figure 1, which relatesto the control of the white lights, it is assumed that the parts are inthe position shown. Relay coils 35 and 33 are equally energized byreason of the above referred to parallel relationship and by reason ofthe -tion causes partial short-circuiting of the relay coil 35 todecrease the energization thereof and increase the energization of therelay coil 36. This unbalanced relationship of the relay coils 35 and 36is afforded by the parallel relationship pointed out above. Thisunbalanced relationship causes movement of the switch arm 38intoengagement with the contact 48 to increase the light intensities ofthe lights II in the manner pointed out above and to rotate the slider33 towards the right with respect to the. balancing potentiometer coil34. Movement of the slider 33 towards the right causes partialshort-circuiting of the relay coil 36 to decrease the energize.- tionthereof and increase the energization of the relay coil 35, it beingremembered that the relay coil 36 was energized more than the relay coil35 by reason of the left hand movement of the slider 48 of the controlpotentiometer I3. When the slider 33 has moved sufliclently far to theright to rebalance the energizations of the relay coils 35 and 36 theswitch arm 38 is moved out of engagement with the contact to the mid-aposition shown to prevent further counter-clock- 4 wise movement of theslider I9 and consequent I 2I and also to rotate the slider 33 to theleft with respect to the balancing potentiometer coil 34. Movement ofthe slider 33 to the left with respect to the balancing potentiometercoil 34 causes partial short-circuiting of the relay coil 35 to decreasethe energization thereof and increase the energization of the relay coil36, it being remembered that the relay coil 35 was energized more thanthe relay coil 36 by reason of the right-hand movement of the controlslider 48. When the slider 33 has moved sufficiently far to the left soas to rebalance the energizations of the relay coils 35 and 36 theswitch arm 38 is moved out of engagement with the contact 39 to themidposition shown. This stops the further clockwise rotation of theslider I9 and further dimming of the lights II is therebyprevented.

In this manner the slider l9 of; the dimmer plate I0 may be made tofollow the slider 48 of the control potentiometer I3 whereby the lightintensities'of the lamps II may be adjusted to any position desired bymanually manipulating the slider 48 of the control potentiometer I3.When the slider 48 of the control potentiometer I3 is moved to thecomplete off position the relay coil 36 is substantially completelyshortcircuited and the slider I9 of the dimmer plate I8 is moved to acomplete clockwise position to open the switch 28 to extinguish thelights II. Likewise, movement of the slider 48 of the controlpotentiometer I3 to the full on position, the relay coil 35 issubstantially completely shortcircuited to move the slider I3 of thedimerplate III to the extreme counter-clockwise position whereby thelights II are brightened to their fullest extent.

After the slider 48 of the control potentiometer I3 has been moved to adesired position to adjust the light intensities of the lamps II and thelight intensities of these lamps have been so adjusted in the mannerpointed out above, the. double pole single throw switch 56 may be openedto break the supply of electrical power to the relay coils 35 and 36 ofthe proportioningmotor I 2. The proportioning motor I2 and consequentlythe dimmer plate III will remain in this adjusted position, since theswitch arm 38 is maintained in a midposition with respect to thecontacts 39 and 40 when the coils 35 and 36 are deenergized. The

slider 48 of the control potentiometer I3 may be then moved to anotherposition but this will not cause operation of the slider I9 of thedimmer plate I0, since the control circuit is rendered inoperative byreason of the switch 56 being open. In this manner the controlpotentiometer I3 may be preset while the proportioning motor I2ismaintained in a desired position. When the switch 56 is subsequentlyclosed to again supply electrical power to the control system, theslider I3 of the dimmer plate I8 is rotated to a position to correspondwith that of the control slider 48 to readjust the light intensities ofthe lights II. Therefore, the light intensities of the lamps II may beadjusted to one value and maintained at that value while the controlslider 48 of the control potentiometer I3 is being moved to anotherposition. Subsequently, when the switch 56 is closed the lightintensities of the lights II are then adjusted to the new positionaccording to the new position of the control slider 48. If the switch 56is maintained closed the light intensities of the lamps 2 I may bemodulated or faded by slowly rotating the control slider 48.

Opening of the manual switch 6'! breaks the connection between theslider 48 of the control potentiometer I3 and the junction of the relaycoils 35 and 36L This prevents the control potentiometer I3 fromunbalancing the relay coils 35 and 36 whereby the control potentiometerI3 is rendered ineffective to control the proportioning motor I2.

The above described mode of operation, wherein the proportioning motorI2 and consequently .the dimmer plate ID are positioned in accordancewith the positioning of the control potentiometer I3, was predicated onthe fact that the sliders 5Il-of the fader. potentiometers I4 werelocated in the midposition shown in the drawing. This midposition of thesliders 58 connects the slider 48 of the control potentiometer I3directly to the junction of the relay coils 35 and 36, whereby the faderpotentiometer coils I4 have no effect upon the relay coils 35 and 36. Aspointed out above, the fader potentiometers I4 are connected in parallelwith the relay coils 35 and 36. By reason of this parallel relationshipmovement of the slider 50 towards the right from the midposition showndecreases the energizatlon of the relay coil 36 and increases theenergization of the relay coil 35 in exactly the same manner as doesright-hand movement of the slider 48 of the control potentiometer I3.This right-hand movetion shown, resistance is addedin series withtheslider 48 of thecontrol potentiometer I3, this resistance beingprogressively placed in series with the slider 48 of the controlpotentiometer I3 and therefore progressively rendering the controlpotentiometer I3 less effective to control the energizations of therelay coils 35 and 36. Therefore, whatever position the slider 48 of thecontrol potentiometer I3. may assume, movement of the slider 50 of thefader potentiometer I4 from the midposition shown in the drawing to theextreme right-hand position causes extinguishment of the lights II.

Conversely, movement of the slider 50 of the fader potentiometer I4 tothe left from the midposition shown in the drawing to the completeleft-hand position progressively operates the proportioning motor I2 tomove the slider I9 of the dimmer plate I to a complete counter-clockwiseposition whereby the intensities of the lights II are increased to 100%brilliancy. Left-hand movement of the slider 50 of the faderpotentiometer 14 also adds resistance in series with the slider 48 ofthe control potentiometer I3 to render the control potentiometer I3progressively less effective to control the proportioning motor I2,Therefore, as the sliders 50 of the fader potentiometers I4 are movedfrom the midposition to either extreme position the control of theproportioning motors I2 is gradually taken away from the controlpotentiometer I3 and the proportioning motors I2 are operated to eitherextinguish the lights II or to increase the light intensities thereof to100%, dependent upon which way the sliders 50 are moved.

As pointed out above, the sliders 50 of the fader potentiometers I4 areconnected together for simultaneous movement, whereupon theproportioning motors I2 associated with the respective faderpotentiometers I4 are moved to either extreme position depending uponthe direction of movement of the sliders 50. As shown in Figure 1, thecontrol potentiometer I3 for the white lights is in a midposition andtherefore the White lights are at 50% brilliancy. I The controlpotentiometer I3 for the blue lights is in a three-quarters on positionwhereby the light intensities of the blue lights are substantially 75%.If the sliders 50 of the fader potentiometers I4 are moved at a rateslower than the maximum rate of movement of the proportioning motors I2,the proportioning motors I2 will be moved towards either extremeposition and both proportioning motors I2 will arrive at that extremeposition at exactly the same time. Specifically, movement of the sliders50 towards the right causes movement of the proportioning motors I2towards the o position whereby the l ghts H are extinguished and thewhite lights and the blue lights are extinguished at exactly the sametime. Similarly, movement of the sliders 50 towards the left causesoperation of the proportioning motors I2 to increase the intensities ofthe lights to 100%, and the white lights and the blue lights will beadjusted to this 100% brilliancy at exactly the same time. Therefore, itfollows that no matter what position the proportioning motors I2 may bein these proportioning motors may be moved to either exfore maintainedin such position as to maintain the lights II extinguished, The sliders48 of the control potentiometers I3 may therefore be adjusted to anydesired position but the motors I2 will remain in the off position.Movement of the sliders 50 from the extreme right-hand position to themidposition shown in the drawing gradually places the control of theproportioning motors I2 under the control of their respective controlpotentiometers I3, and when the sliders 50 are finally moved to themidposition shown in the drawing the proportioning motors I2 will assumepositions corresponding to the positions of their respective controlpotentiometers I3, and if the sliders 50 of the fader potentiometers I4are moved at a rate slower than the maximum speed of the proportioningmotors I2, the proportioning motors I2 will arrive at their desiredpositions at exactly the same time. In this manner the lights may bebrightened in a proportionate manner from an oif" condition to a desiredcondition and the rate of travel of the proportioning motors I2 is socontrolled that the proportioning motors I2 will arrive at their desiredpositions at exactly the same time. By use of the above constructiontrue proportionate dimming and true proportionate brightening of thevarious lights are obtained.

Generally speaking, the maximum electrical capacity of a single dimmerplate is about 3600 watts. It may be desired to control a lamp loadgreater than 3600 watts from a single control potentiometer I3. This maybe accomplished in two ways: One, by using the core type reactor forcontrolling the lamp load as pointed out above, or, two, by using aplurality of resistance type dimmer plates, and this latter method isdisclosed in Figure 1. The lighting load, designated as white lights,may be split up into two loads II and II, the load II being controlledby the resistance type dimmer plate I0 in the manner pointed out above,and the load II being controlled by the resistance type dimmer plateIll. The dimmer plate l0 may be controlled by another proportioningmotor I2, the construction of which is identical with that of I2. Themotor I2 may be supplied with power from'the line wires I5 and I6 bywires 43', 43 and 44 and 45', 45 and 46. The relay coils 35 and 36' maybe connected to the control potentiometer I3 by wires 51, 58 and 68' inthe same manner that the relay coils 35 and 36 of the proportioningmotor I2 are connected thereto; The resistances 68 and 69' in theproportioning motors I2 and I2' are provided so that the twoproportioning motors I2 and I2 will operate identically in response tomovement of the control slider 48 .of the control potentiometer I3, orin response to the slider 50 of the fader potentiometer I4. The specificmanner in which this mode of operation is accomplished is set forth inan application Serial No. 33,070 filed by myself and Lewis L. Cunninghamon July 25, 1935. By reason of this construction a single controlpotentiometer identically positions two or more resistance type dimmerplates. Like elements of the proportioning motor I2 have been designatedby like reference characters primed so that the operation of theproportioning motor I 2 may be easily followed upon reference to theoperation eter coil 41, the fader potentiometer coil 49 and the relaycoil 36 have been designated as B, and the slider 48 of the controlpotentiometer I3, the slider 50 of the fader-potentiometer I4 and thejunction of the relay coils 35 and 36 have been designated as R. Thedesignations W, B and R represent respectively white, blue and red, andupon reference to the accompanying Figures 2 to '7 it will be noted thatthe white connections of ,the various potentiometers are connected tothe white connections of the proportioning-motors, the blue of thevarious potentiometers are connected to the blue of the propor-tioningmotors, and likewise the red of the various potentiometers are connectedto the red of the proportioning motors, in exactly the same manner asthey are connected in Figure 1. .These designations of white, blue andred are made to facilitatethe description of my invention as disclosedin Figures 2 to 7. When the sliders of the various potentiometers aremoved towards 'the white connection the light intensities of the lampsare increased and when the sliders are moved towards the blue the lightintensities are decreased, and when the sliders are in the extremeblue'position the lights are extinguished. The power connections to thevarious proportioning motors I2 are designated by the characters A andB.

Now that the general mode of operation 01 the basic principles of myinvention are understood, reference is now made to'the remaining figuresof the drawing, wherein there are disclosed various combinations of mycontrol system illustrated in Figure 1, to arrive at new and novelresults never before obtained in the art of lighting control systems.

Figures 2 and 3 Referring now to Figures 2 and 3, I have shown one formof my invention which utilizes the above described principles ofoperation to afford control of lights from remotely located controlpanels. In Figure 2 is illustrated one control panel which may belocated in any convenient place such as the stage of a theatre, having aplurality of control potentiometers I8 for controlling a plurality ofproportioning motors I2 shown in Figure 3. The proportioning motors I2operate current controlling devices and may be located near theirrespective lamp loads. By placing Figures 2 and 3 side by side acomposite wiring diagram of the complete system may be obtained. Asshown in Figure 2 for purposes of illustration only, there are threesets of control potentiometers l3 and they are designated as No. 1preset, No. 2 preset and No. 3 preset." Each preset is shown to have aplurality of control potentiometers I3 and these control potentiometersare designated as foots, No. 1 border, and No. 2 border. The controlpotentiometers I3 of the three presets designated foots are adapted tocontrol the proportioning motor I2 in Figure 3 designated foots. Thecontrol potentiometers l8 of the three presets designated No. 1 borderare adapted to con-,

trol the proportioning motor I2 of Figure 3 deson switch generallydesignated at E6, each preset being provided with one of these switches.

Each switch 16 is adapted to operate a relaygenerally designated at I5for placing the various presets inand out of operation.

The control panel illustratedin Figure '2 may be placed in operation bya master control generally designated'at I1 and illustrated at thebottom of Figure 2. The various proportioning motors I2 shown in Figure3 may be controlled also by another control panel located at some otherpoint, such as the projection booth of a theatre, and this secondcontrol panel may in all respects be the same as the control panelillustrated in Figure 2. This second control panel may be placed inoperation by means of a master control 18 shown in the lower right-handportion of Figure 3. The master controls 11 and 18 of the two controlpanels are so arranged and interlocked that only one control panel maybe in operation at a time.

Power is supplied to the connections A and B of the variousproportioning motors I2 by means of the line wires I5 and I6 leadingfrom some source of power, not shown. Power may be supplied to thecontrol panels and consequently the control systems by means of astep-down transformer having a primary 8I and a secondary 82. Thesecondary 82 may be connected by wires 83 and 84 to a lock switch 85 onthe first control panel. The secondary 82 of the step-down transformer80 may also be connected by wires 86 and" 81 to a lock switch 88 locatedon the second control panel. The lock switch 85 is connected by wires 89and 90 and switches 9I and 92 to busses 93 and 94 which deliver power tothe control devices on the first panel. switches 9I and 92 are closedthe busses 93 and 94 are supplied with power so that the various controlpotentiometers I3 on the first panel may control the variousproportioning motors I2. The switches 9I and 92 are controlled by arelay coil 95 and this relay coil 95 in turn controls other switches 96,91 and 98. When the relay coil 95 closed and when the relay coil 95 isdeenergized these switches are opened and theswitch 98 is closed asshown in Figure 2.

In a like manner, the lock switch 88 of the second control panel isconnected by wires 99 and I00 and switches IM and I02 to busses I03 andI04 which supply power to the control potentiometers of the secondpanel. The switches IN and I02 are controlled by a relay coil I05 whichalso controls switches I08, I01 and I08. The arrangement is such thatwhen the relay coil I05 is energized the switches I0l, I02, I06 and I01are closed and when the relay coil I05 is deenergized these switches areopened and the switch I08 is closed as shown in the lower portion ofFigure 3.

' The master controls 11 and I8 of the two control panels are eachprovided with momentary switches [I0 and I2I respectively. Assume thatthe lock switch 85 of the. first control panel is closed and that themomentary switch H0 is moved to a closed position. A circuit is thencompleted from the secondary 82 through wire 8!, lock switch 85, wire90, relay coil 95, wire I I I, momentary switch IIO, wires H2 and 89,lock switch 85 and wire 83 back to the secondary 82. Completion of thiscircuit causes energization of the relay coil 95- to close the switches9| and 92 to supply power to the busses 93 and 94. Finergization of therelay coil 95 also closes the switch 96 to complete a maintainingcircuit from the secondary 82 through wire 84, lock switch 85, wire 90,relay coil 95 switch 96, wire II3, switch When the I08 of the mastercontrol 18 of the second control panel, and wires II 4 and 86 back tothe secondary 82. Completion of this circuit maintains the relay coil 95energized even though the momentary switch H is subsequently opened. Inthis manner the supply of power to the busses 93 and 94 is maintained. Agreen pilot light II connected across the busses 93 and 94 indicatesthat the first control panel is energized and ready for operation.Closing of the switch 91 by the energization of the relay coil 95completes a circuit from the secondary 82 through wires 83 and H6,switch 91, wire 1, a red pilot light II8 on the second control panel,and wires H9 and 81 back to the secondary 82. This causes lighting ofthe red pilot light .on the second control panel to warn the operatorthereof that the control potentiometers I3 of the first control panelare in control of the various proportioning motors I2.

If the operator of the second control panel should decide to take overthe control of the various proportioning motors I2, he opens the lockswitch 88 and closes the momentary switch I2I. This completes a circuitfrom the secondary 82 through wire 86, lock switch 88, wires 99 and I22,momentary switch I2I, wire I23, relay coil I05, wire I00, lock switch 88and wire 81 back to the secondary 82. Completion of this circuit causesenergization of the relay coil I05 to close the switches I02, IOI, I06and I0! and to open the switch I08. Closure of the switches I02 and I Msupplies power to the busses I03 and I04 of the second control panel.Opening of the switch I08 breaks the maintaining circuit for the relaycoil 95 of the first control panel whereby the switches 9|, 92, 96 and91 are opened and the switch 98 closed. This stops the supply of powerto the busses 93 and 94 of the first control panel. Closure of theswitch I08 upon energizetion of the relay coil I05 completes a circuitfrom the secondary 82 through wire 81, lock switch 88, wire I00, relaycoil I05, switch I06, wire I24, switch 98 which was closed by thedeenergization of relay coil 95, and wires H6 and 83 back to thesecondary 82. This completes a maintaining circuit for the relay coilI05 to maintain the supply of power to the busses I03 and I04 of thesecond control panel. A green pilot light I25 connected across thebusses I03 and I04 indicates that the second control panel is incondition for operation. Closure of the switch I01 completes a circuitfrom the secondary 82 through wires 86 and H4, switch I01, wire I26, redpilot light I2I on the first control panel, and wires I28 and 84 back tothe secondary 82. Completion oi this circuit causes lighting of the redpilot light on the first control panel to indicate that the secondcontrol panel is in control of the various proportioning motors I2.

From the above it is seen that I have provided an interlocking switchingmechanism for supplying power to one control panel or another controlpanel along with means for indicating at each control panel whichcontrol panel is in operation. It is impossible to supply power to bothcontrol panels at the same time. The lock switches 85 and 88 areprovided to prevent haphazard operation of these control panels so thatonly those persons who have keys for the lock switches may control theoperation of the various proportioning motors. Although I have disclosedmaster controls for only two control panels it is obvious that thenumber of master controls and the number of control panels may beincreased as desired.

The relays I5 which place the control potentiometers I3 of the variouspresets in control of the 'proportioning motors I2 may comprise a relaycoil I30 for operating switches I3I to I42 inelusive. the relay coil I30is energized the switches I3I and I34 to I42, inclusive, are closed andwhen the relay coil I30 is deenergized these switches are opened and theswitches I32 and I33 are closed. The relays 15 for the various presetsare identical and like reference characters have been used to designatelike elements. The on-andoff switches 16 which control each of therelays I5 may comprise an on button I44 and an ofi button I45.

Assume the parts in the position shown in Figure 2. Movement of the onbutton I44 of the first preset to a circuit closing position completes acircuit from the bus 94 through the on button I44, relay coil I30 and "obutton I45 to the other bus 93. Completion of this circuit causesenergization of the relay coil I30 to perform the above mentionedswitching functions. Closure of the switch I3I by energization of therelay coil I30 completes a maintaining circuit for the relay coil I30 ofthe first preset from the bus 94 through switch I32 of the third preset,through switch I33 of the second preset, through switch I 3I of thefirst preset, relay coil I30 and off button I45 of the first preset backto the other bus 93. Completion of this circuit maintains the relay coilI30 of the first preset energized as long as the switch I33 of thesecond preset and the switch I32 of the third preset are closed. Therelay coil I30 of the first preset may be deenergized by opening the oilbutton I45 of the first preset or by opening the switches I33 and I32 ofthe second and third presets respectively.

In a like manner closure of the on button of the second preset energizesthe relay coil I30 of the second preset, and closure of the switch I3Iupon energization of the relay coil I30 of the second preset completes amaintaining circuit from the bus 94 through switch I32 of the firstpreset, switch I33 of the third preset, switch I3I'of the second preset,relay coil I30 of the second preset, and off button I45 of the secondpreset to the bus 93. Similarly, the relay coil I30 of the th rd presetis energized by closure of the on button I44 associated therewith, andthe relay coil I30 is maintained energized through a circuit from thebus 94 through switch I32 of the second preset, switch I33 of the firstpreset, switch I3I of the third preset, relay coil I30 of the thirdpreset, and off button I45 of the third preset back to the other bus 93.It is noted at this point that the'switches I32 and I33 of each presetare included in the maintaining circuits of the relay coils I30 ofthevarious presets. It therefore follows that each relay coil I30 ofeach preset may be energized by closure of the on button associated withthat relay and may be deenergized by opening of the oil buttonassociated with that relay. It also follows that if the relay'coil I30of one preset is energized closure of the on button of any other presetdeenergizes that first relay coil and energizes the second relay coil,whereby when one preset is placed in control the other presets areautomatically rendered inoperative.-

Located on the control panel adjacent each preset is a pilot light I41which is lighted through a circuit from the bus 93 through switch I38 ofits associated relay I5 and the pilot light I41 The arrangement is suchthat when back to the other bus 94. Therefore, when any preset is inoperation the pilot light I41 associated therewith is lighted toindicate this fact.

Closure of the switch I34 of the first preset connects the blues of thecontrol potentiometers I3 of that preset to the bus 94, and likewise,closure of the switch I35 of the first'preset conmeets the whites of allof the control potentiometers I3 of that preset to the bus 93. Closureof the switch I36 of the first preset connects the bus 94 and the bluesof the control potentiometers I3 to a conductor I49 which extends to theblues of all of the proportioning motors I2.' Likewise,

closure of the switch I31 connects the'bus 93 and the whites of thecontrol potentiometers I3 of the first preset to a conductor I50 whichextends to the whites of all of the proportioning motors I2. In thismanner the whites and blues of the control potentiometers I3 and theproportioning motors I2 are connected together in parallel and acrossthe busses. 93 and 94 in the manner illustrated in Figure 1.

Closure of the switch I4I connects the red of thecontrol potentiometerI3 designated foots, to a conductor I5I which extends to the red of theproportioning motor I2, designated foots. Likewise, closure of theswitch I40 connects the red of the control potentiometer I3 designatedNo. 1 border to a conductor I52 which extends to the red of theproportioning motor I2 designated N0. 1 border. Similarly, closure ofthe switch I39 connects the red of the control potentiometer I3designated No. 2 border to a conductor I53 which extends to thepotentiometers I2 and I2 designated No. 2 border. Other controlpotentiometers may be connected in parallel with the controlpotentiometers I3 shown in Figure 2, and the reds of these controlpotentiometers may be connected through suitable switches operated bythe relays I30 to the reds of other proportioning motors. Specifically,the red of one of these other control potentiometers may be connected toa conductor I54 upon closure of the switch I42, the conductor I54leading to the red of the proportioning motor I2 designated Othermotors. Therefore, it is seen that any number of proportioning motors I2and any number of control potentiometers I3 may be utilized and stillremain within the concept of my invention.

From the above connections it is seen that when the relay coil I30 ofNo. 1 preset is energized the control potentiometers I3 of No. 1 presetare connected to the proportioning motors I2 in the manner illustratedin Figure 1, and these proportioning motors I2 will assume positionscorresponding to the positions of the various sliders of the controlpotentiometers I 3, the operation of which was specifically referred towith respect to Figure 1. In a like manner energization of the relaycoil I30of No. 2 preset places the proportioning motors I2 under thecontrol of the control potentiometers I3 of the No. 2 preset. Similarly,energization of relay coil I30 of fNo. '3 preset places the controlpotentiometers I3 thereof in control of the proportioning motors I2. v

Summarizing briefly the operation of this portion of the invention, thevarious control potentiometers I3 of No. 1 preset may be positioned asdesired, and when the relay coil I30 of No. 1 preset is energized, theproportioning motors I2 will assume positions corresponding to thepositions of their respective control potentiometers 53 of No. 1 preset.After the proportioning motors I2 have moved to the desired positionsthe relay coil I30 may be deenergized by opening the off button I45 andthe' proportioning motors will remain in the position that they assume.Since the'connections to the proportioning motors are broken bydeenergization of the relay coil I30, the control potentiometers I3 ofthe No; 1 preset may be placed in other desired positions, and when theon contact I44 is closed to energize the relay coil I30 of No. 1 preset,the proportioning motors I2 will then assume the new position asdetermined by the new positions of the control potentiometers of No 1preset.

If it be desired to go .directly from one preset toanother preset, asfor example, from the first preset to the second preset, the on buttonof the second preset may be closed to energize the relay coil I30 of thesecond preset which automatically renders the first preset inoperativeto control the proportioning motors 'I-2 and places the control of theproportioning motors I2 under the second preset, the proportioningmotors I2 assuming positions corresponding to the positions of thecontrol potentiometers I3 of the second preset. Similarly, energizationof the relay coil I30 of the third preset places the second preset outof control of the proportioning motors I2 and places the proportioningmotors I2 under the control of the control potentiometers I3 of thethird preset, and the proportioning motors I2 will move to positions tocorrespond with the settings of the control potentiometers I3 of thethird preset.

If it be desired to extinguish the lights, the control potentiometers I3of one of the presets may be adjusted to the extreme blue or offposition, and when the proportloning motors I2 are placed under thecontrol oi this preset the proportioning motors I2 will be operated toan "o position, thereby extinguishing the lights operated thereby.

- The sliders of the various control potentiometers I3 are adapted tooperate a switch I56, the arrangement being such that when the slidersare in the extreme blue or off position the switch I56 is opened andwhen the sliders are moved out of these extreme blue or o positions theswitch I56 is 'closed. The switch I 56 is adapted to control a pilotlight I51 associated with each control potentiometer I3. When the switchI38 operated by the relay coil I30 is closed upon placing the particularpreset in operation, a circuit is completed from the bus 93 throughswitch I38, switch I56 and pilot light I51 back to the bus 94, providingthe control potentiometer is not in the extreme blue or off position.Therefore, when the control potentiometer I3 is in such position as tocause lighting of the lamps controlled there by and when the particularpreset is placed in control of the various proportioning motors I2, thepilot light I51 is lighted and indicates that the various controlpotentiometers I3 are in a lighting position.

Figure 4 Referring now to Figure 4. I have shown a cated controlpotentiometer I3. As shown in the drawings, the control system isdivided up into three groups designated white stage, red stage and "bluestage", for controlling the white lights, the red lights and the bluelights respectively. Although I have shown only three groups, as manymore groups as may be desired may be utilized. Also, as shown in Figure4, each group comprises three control potentiometers I3 controllingthree proportioning motors I2, one of these potentiometers controllingthe foots, another controlling the No. 1 border, and another controllingthe "No. 2 border proportioning motors. It is within the contemplationof this invention to include more than three control potentiometers I 3and three proportioning motors I2 within each group.

Power is supplied to the connections A and B of the variousproportioning motors I2 by line wires I5 and I6. Power is supplied tothe control system through the step-down transformer 80 having a primary8| and a secondary 82, the primary 8I being connected to some source ofpower, not shown, and the secondary 82 being connected to a lock switch85. This portion of the'invention contemplates the use of a blackoutswitch generally designated at I80 for extinguishing all of the lights,the operation of which will be pointed out more fully hereafter. Thisblackout switch I60 may comprise an operator I6I for controllingswitches I62 to I15 inclusive. The arrangement is such that when theoperator I61 is in the position shown in the drawings the switches I62to I13 inclusive are opened and switches I14 and I15 are closed. Whenthe operator I6I is moved downwardly from the position shown in thedrawings the switches I62 to I13 inclusive are closed and the switchesI14 and I15 are opened. This invention also contemplates the use of astage main switch I11 comprising switches I18 and I18, a color switchI80 for the blue stage group, comprising switches I8I and I82, a colorswitch I83 for the "red stage group, comprising switches I84 and I85,and a color switch I86 for the white stage group, comprising switchesI81 and I88.

The lock switch 85 when closed supplies power to busses I90 and ISI. Thebus I80 is connected to the whites of all of the proportioning motors l2and to the switch I15 of the blackout switch I 60. The bus I9I isconnected to the switch I14 of the blackout switch I60 and is alsoconnected to the movable contacts of switches I62 to I13 inclusive ofthe blackout switch I60. The switches I14 and I15 of the blackout switchI60 are connected respectively to the switches I18 and .I19 of the stagemain switch I11. The switches I18 and I19 of the stage main switch I11are in turn connected to the switches I8I and I82 of the color switchI80, switches I84 and I85 of the color switch I83, and the switches I81and I88 of the color switch I86. The arrangement is such that theswitches'of the color switches I80, I83 and I86 are arranged in paralleland the switches of the stage main switch I11 are arranged in serieswith the color switches. The switch I8I of the color switch I80 isconnected to the blues of the control potentiometers I3 of the bluestage group and the switch I82 is connected to the whites of the controlpotentiometers I3 of the- "blue stage group. In a like manner, theswitches I84 and I85 are connected respectively to the blues and whitesof the control potentiometers I3 of the red stage group. Similarly, the

switches I81 and I88 are connected to the blues and whites respectivelyof the control potentiometers I3 of the white stage group. The blues ofthe control potentiometers 13 of each group are connected to the bluesof the proportioning motors I2 of that group. The red of each controlpotentiometer I3 is connected to the red of its associated proportioningmotor I2. From the above wiring connections it is seen that the blues ofthe control potentiometers I3 and the blues of the proportioning motorsare directly connected together and that power is supplied to the bluesof both the control potentiometer I3 and the proportioning motor I2through the switch I14 of the blackout switch I60. It is also seen thatpower is at all times supplied to the whites of the proportioning motorsI2 and that the whites of the control potentiometers I3 are connected tothe whites of the proportioning motors I2 and to the bus I90 through theswitch I15 of the blackout switch I60. Therefore, with the switches inthe position shown in the drawings the whites, blues and reds of thecontrol potentiometers are connected to the whites, blues and reds ofthe associated proportioning motors I2 and to the secondary 82 of thestep-down transformer 80 in manner illustrated in Figure 1., 7

By reason of these connections the proportioning motors I2 will assumepositions corresponding to the positions of their associated controlpotentiometers I3 in a manner pointed out above with respect toFigure 1. Opening of the color switch I80 stops the supply of power tothe control potentiometers I3 of the blue stage group and theproportioning motors I2 will remain in the positions corresponding tothe positions of the control potentiometers I3. Since the supply ofpower to the control potentiometers I3 is prevented by the opening ofthe color switch I80. these control potentiometers may be adjusted tonew positions, and when the color switch I80 is v positions inaccordance with the new settings of the control potentiometers I3 ofthat group. In this manner presetting oi the control potentiometers ofthe blue stage group may be accomplished. The color switches I83 and I86of the red stage group and "white stage group respectively performexactly the same function. When the switches I83 or I86 are opened thecontrol potentiometers I3 of either group may be adjusted to newpositions without affecting the present positions of the proportioningmotors I2 of those groups.- Upon subsequent closure of the colorswitches I83 or I86 the proportioning motors of the "red stage grouporthe white stage group will assume new positions in accordance with thepositions of the control potentiometers I3 of those groups.

Since the stage main switch I11 stops the supply of power to all of thecontrol potentiometers I3 upon opening thereof, pre-setting of all ofthe control potentiometers at one time is provided, and when the stagemain switch is subsequently moved to a closed position all of theproportioning motors I2 will be moved to the new positions determined bythe positions of their associated control potentiometers I3.

I By reason of the above construction a lighting control system isprovided wherein the motors and control potentiometers are divided intoa plurality of groups, and wherein each group con- ,tains a plurality ofmotors and control potentistage group are connected to the switch I64 ofthe blackout switch I60. Likewise, all of the blues of the proportioningmotors I2 of the red stage group are connected to the switch I63 and allof the blues of the proportioning motors I2 of the white stage group areconnected to the switch I62. Readingfrom right to left, the red. of eachproportioning motor I2 is connected respectively to switches I65 to'I13inclusive. The movable contacts of switches I62 to I13 inclusive areconnected together and to the bus I3I. The whites of all of theproportioning motors I2 are connected to the bus I30.

Movement of the. operator ,I6I of the blackout switch I downwardlycloses switches I62 to I13 inclusive and opens switches I14 and I15.Opening of the switches I14 and I15 stops the supply of power tofthecontrol potentiometers I3 of all of the groups to render thesecontrolpotentiometers inoperative to control the proportioning motors I2in the same manner as does the stage main switch I11. Closure of theswitches I62, I63 and I34 connects the blues of all of the proportioningmotors. I2 to the bus I3I and since the whites of all of theproportioning motors I2 are connected to the bus I30, power is suppliedto the relay coils 35 and 36 (Figure 1) of the proportioning motors I2.Closure of the switches I to I 13 inclusive connects the red and blue ofeach proportioning motor I2 whereby the coil 36 (Figure 1) issubstantially completely short-circuited. This causes movement of theproportioning motors I2 to a comple te of! position since completeleft-hand movement of the slider 33 oi! the balancing potentiometer(Figure 1) to the left is required to rebalance the coils 35 and 36. Inthis manner movement of the operator I 6| of the blackout switch I30downwardly causes a simultaneous movement oi all of the proportioningmotors I2 to an 0115 position. Upon movement of the operator I6Iupwardly to the position shown in the drawings, the connections betweenthe blue and red 01' each of the proportioning motors is broken wherebythe short-circuit of the relay coil 36 (Figure, 1) is likewise broken,and since the switches I14 and I13 01 the blackout switch I60 are closedthe control of the proportioning moto'rs I2 is returned to theirrespective control potentiometers I3 and the proportioning motors I2will be moved to positions corresponding to the positions of theirassociated control potenti ometers I3.

Summarizing briefly the mode of operation 61 the lighting control systemillustrated in Figure 4, it is seen that the proportioningmotors I2 ofeach stage group are controlled by the control potentiometers I3 01'that group, that each group may be preset by reason of the color switchfor that group, and that all groups may be preset by reason of the stagemain switch. Provision is made for moving all of the proportioningmotors I2 simultaneously to an "off position where- I by all or thelights will be extinguished, this last mode oi operation beingaccomplished by means v ofa single blackout switch. When the blackoutswitch is restored-to the normal p sit a l of are closed.

trol potentiometers I3 providing the stage main' switch and the colorswitches of each color group I Figure 5 In Figure 5 I have shown alighting control system somewhat similar to that shown in Figure 4 andwhich also utilizes the principles of operation shown in Figure 1. Likethat of Figure 4, the control system of Figure 5 is divided into aplurality of groups designated as white stage group, red stage group,and blue stage group. In each group are a plurality of controlpotentiometers I3 which are designated foots, "No. 1 border, and No. 2border. However, the control potentiometer I3 designated foots has beenomitted from the red stage group and the blue stage group in order toconserve space on the drawing. Each control potentiometer I 3 is adaptedto control a proportioning motor I2 in the manner pointed out above withreference to Figures 1 and 4. As in Figure 4, each group of controlpotentiometers I3 is provided with a color switch to allow .presettingof the control potentiometers of that group. Likewise, there is shown astage main switch for allowing presetting of all of the controlpotentiometers I3 of all of the groups. The various color switches andthe stage main switch have been indicated by the same referencecharacters that they are indicated by in Figure 4. As in Figure 4, thenumber of groups and the number of control potentiometers I3 in eachgroup maybe increased as desired. The blackout switch I60 of Figure 4 isnot shown in Figure 5.

Master control potentiometers I35, I36 and I31 are provided for the"white stage, the "red. stage" and the blue stage groups respectively.

The purpose of these master control potentiometers is to provide a meanswhereby all of the lights of one group may be controlled by asinglemaster control potentiometer. A stage master control potentiometer isdesignated at I33 and the purpose of this potentiometer is to provide ameans whereby all of the lights of all of the stage groups may becontrolled by a single potentiometer.

/ Power is supplied to the connections A and B of the proportioningmotors I2 by means 01' the line wires I5 and I6, and power is suppliedto the control system by meansof the step-down transformer-30, theprimary 3| of which is connected across the wires I5 and I6. The sec--ondary 32 of the step-down transformer 33 is connected to the lockswitch 33 which intum is connected to busses I30 and MI. The busses I30and I3I are connected to the switches I 13 and I13 of stage main switchI11, and the switches I13 and I13 are-in turn connected respectively tothe switches III and I82 of the color switch 130 of the "blue stagegroup, the switches I33 and I35 of the color switch I33 of the red stagegroup, and the switches I31 and I33 of the color switch I36 of the whitestage group. The color switches' I00; I83 and I36 are connected inparallel with respect to each other and in series with the stage mainswitch I11. The bluesand whites of the control potentiometers I3 and ofthemotors I2 ofthe white stage group are connected to the switches I31and I33 respectively of the color switch I36. In a like manner the bluesand whites of the control potentiometers I3 and of the proportioningmotors I2 of the red stage group are connected respectively to theswitches ,blue stage, group are connected respectively to the switchesI8I and I82 of the color switch I88. The master control potentiometersI95; I98 and I91 are connected in parallel with the blues and whites ofthe control potentiometers I3 of their respective groups. The blue andwhite of the stage inaster control potentiometer are connected to theswitches I18 and I19 respectively of the stage main switch I". From theabove wiring connections it is seen that when all of the color switchesI88,,I88 and I88 and the stage main switch I" 'are closed the blues andwhites of all of the motors are connected across the busses I98 and I9I.In order to switch the control of the proportioning motors I2 of a groupfrom the control potentiometers II of that group to the master controlpotentiometer of that group I have provided control switches 208. Inorder to extend the control 01 the proportioning motors I2 of any groupfrom the control of the master control potentiometer of 'that group tothe stage master control potentiometer I98 I have provided the controlswitches 2III. In order to transfer the control of all of theproportioning motors I2 from the stage master control potentiometer I98to a remotely located control station Ihave provided a control switch282.

With the control switches 298, 2III and 282 in the positions shown inthe drawings it is seen that the reds of the control potentlometers I3are connected to the reds of their associated proportioning motors I2.In this manner the control potentiometers II are connected to theproportioning motors I2 in the manner indicated in Figure 1,- and theproportioning motors I2 will assume positions corresponding to thepositions of their associated control potentiometers I3. The colorswitches I88, I88 and I88 stop the supply of power to the controlpotentiometers I3 whereby presetting of these control potentiometers inthe manner pointed out in connection with Figure 4 is accomplished, andmovement of the stage mainswitch I" to an open position stops the supplyof powerto all of the control potentiometers I8 whereby all of thecontrol potentiometers'may be preset, also in the manner pointed outwith respect to Figure 4.

Movement of the'switches 208 downwardly breaks the connection betweenthe red of the proportioning motors I2 and the red of the r tive tocontrol the proportioning motors I2. This' downward movement of thecontrol switches2fl8 connects all of the reds oi the proportioningmotors I2 of a given group to the red of the master controlpotentiometer of that group. Specifically, the reds-oi the proportioningmotors of the blue stage group are connected to the red of the mastercontrol potentiometer I91 of the "blue stage group. Similarly, the redsof the master potentiometers I95 and I88 the "white stage group and the"red stage group are connected to the reds of .the proportioning motorsI2 of their respective groups. In this manner the 'proportioning motorsI2 of each group are placed under the control of the master controlpotentiometer oi. that group and the proportioning motors I2 will assumepositions corresponding to the positions of the master controlpotentiometers. Opening of the color switch of any group breaks thesupply of power to the master control potentiometer of that groupwhereby the master control potentiometer of that group may be preset inthe manner pointed out in connection with Figure 4.

If it be desired to place all of the proportioning motors I2 of all ofthe groups under the control of the stage master control potentiometerI98 the switches 288 and 20I are moved downwardly, whereby theconnection between the reds of the proportioning motors and the reds ofthe control potentiometer's I3 and the master control potentiometersI95, I96 and I91 are broken. This downward movement of the controlswitches 208 and 2III connects the redsof all of the proportioningmotors I2 to the red of the stage master control potentiometer I98whereby the stage master control potentiometer I98 is connected to theproportioning motors I2 in the manner illustrated in Figure 1, and theproportioning motors I2 will assume positions corresponding to theposition of the stage master controller I 98. Opening of the stage mainswitch 111 permits presett'ing of the stage master control potentiometerwith; out movement of the proportioning motors I2 until such time asthestage main switch I" is a ain closed, whereupon the proportioningmotors I2 will move to new positions corresponding to the positions ofthe stage master control potentiometer I98.

If it be desired to control all of the proportioning motors I2 from aremotely located control station, the control switches 290, 20I and 202are moved downwardly to break the connections between the reds of theproportioning motors I2 .and the reds'ofi; the control potentiometersI3,

the reds of the master control potentiometers I 95, I98 and I91 and thered of the stage master control potentiometer I98. Downward movement ofthe control switch 292 connects the reds of all of the proportioningmotors I2 to the red of a reand each group comprises a plurality ofcontrol potentiometers and associated proportioning motors to bepositioned thereby. Each group is also provided with a master controlpotentiometer and suitable control switches whereby all of the lights ofthat group may be controlled by the master control potentiometer. Eachgroup is also provided with a color switch whereby the controlpotentiometers of that group or the master control potentiometer of thatgroup may be preset while the proportioning motors remain in a givenposition. A stage master control potentiometer and suitable controlswitches are provided whereby the control of all of the proportioningmotors may be placed under the control of the stage master controlpotentiometer. A stage main switch is provided to allow presetting ofthe control potentiometers of all of the groups, the master controlpotentiometer of all of the groups or the stage master controlpotentiometer, but still maintaining the proportioning motors in theirgiven position while adjustment is being made. Provision is also madefor controlling all til stepdown transformer of the proportioning motorsfrom a distant control station. Figure 6 Referring now to Figure 6, Ihave shown another form of my invention wherein proportioning motors |2may control the white lights of the V eters l3 in the manner illustratedin Figure 1.

The control potentiometers l3 are arranged in presets designated No. 1preset and No; 2 preset. Each preset has a control potentiometer l3 forcontrolling one of the proportioning motors l2 and these controlpotentiometers are arranged and designated as foots No. 1 border and No.2 border. Although I have shown only two presets and only three controlpotentiometers in each preset, it is within the contemplation of thisinvention to increase the number of presets and to increase the numberof control potentiometers l3 in each preset and the number ofproportioning motors l2 as desired.

The control potentiometers l3 of the various presets are placed incontrol of the proportioning motors by means of preset switchesgenerally designated at 205 which, for purposes of illustration, areshown to be manually operated by means of a knob 206. These switches205, however, may be electrically operated in the manner illustrated inFigure 2. This form of the invention also utilizes fader potentiometersll for proportionately dimming or brightening the lights in the mannerillustrated in connection with Figure 1. These fader potentiometers l4aredesighated as foots No. 1 border and No. -2

border for controlling their respective proportioning motors |2.

In order to adjust the proportioning motors l2 to vary the lightintensities without breaking any preset, I "have provided rehearsalpotentiometers generally designated at 208, whereby each or all of theproportioning motors l2 may be adjusted as desired. This portion of theinvention finds particular utility in stage lighting systems forrehearsal purposes or where a quick change in the lighting-effect isdesired without breaking any preset. The rehearsal potentiometers 200are placed'in control of the proportioning motors ,|2 by means of doublepole double throw preset release-switches. 209 comprising switch arms 0and 2| I. Power is supplied to the rehearsal potentiometers 208 by meansof a rehearsal switch generally designated at 222.

The preset switches 205 comprise switches M2 to 220 inclusive, thearrangement being such that when the manual operator 200 is moveddownwardly these switches are made and when the Power is supplied to thecontrol system by a 80 having a secondary 82 and a primary 0| which isconnected across 'the line wires I5 and I5. The secondary 02 isconnected to a lock switch 85, and when the lock switch 05 is closedpower is supplied to busse's 224 and 225 which extend to the rehearsalswitch 222.

Thebus 224 is connected to the movable switch arms of the switches 2l5,2|8 and N9 of the preset switches 205, the stationary contacts thereofbeing connected respectively to the whites of manually operated knob 206is moved upwardly. the switches are broken.-

- connected to the blues of the fader potentiometers H, the blues of thecontrol potentiometers I3, and to the blues of the proportioning motorsl2. The switch arms 2|0 of the 'preset release switches 209 areconnected to the whites of the proportioning motors l2. The reds of theproportioning motors l2 are connected to the switch arms 2 of the presetrelease switches 209, and the lower contacts associated with theseswitch arms 2 are connected to the reds, of the fader potentiometers H.The center taps of the fader potentiometers I4 are connected through theswitches 2|2, 2|3 and 2 of the preset switches 205 to the reds of thecontrol potentiometers l3.

From these connections it is seen that when the preset release switches209 are in the position shown in the drawings, when the sliders of thefader potentiometers M are in the midposltion shown in the drawings, andwhen the preset switch 205 of No. 1 preset is closed, the whites of theproportioning motors l2 are connected to the whites of the controlpotentiometers l3 of the No. 1 preset, to the whites of the faderpotentiometers M, and to the bus 224. The blues of the proportioningmotors I2 are connected to the blues of the control potentiometers l3 ofNo. 1

preset, the blues of the iader potentiometers l4, and to the bus 225.The reds of the proportioning motors are connected to the reds of theirrespective control potentiometers l3 of No. 1 preset through the switcharms 2| the center taps and sliders of the fader potentiometers l4.Therefore, the proportioning motors |2 are connected to the controlpotentiometers l3 of No. 1 preset in exactly the same manner as they areconnected in Figure 1, and therefore the proportioning motors |2 arecaused to assume positions corresponding to the positions of the controlpotentiometers l3 of No. 1 preset.

Opening of the preset switch 205 of No. 1 preset breaks the connectionsbetween the control potentiometers l3 of that preset and theproportioning motors |2,whereby the proportioning motors |2 may remainin their present positions while the control potentiometers |3of No.' 1preset are being adjusted to new positions. Upon subsequent closures ofthe preset switch 205 of No. 1 preset the proportioning motors |2 willbe caused to assume new positions corresponding preset. The controlpotentiometers I3 01 "No. 2

prese may be preset in exactly the same manner as those of No. 1 preset.

Assume that the preset switch 205 of the No; 1 preset is closed wherebythe proportioning motors l2 are positioned in accordance with thepositions of the control potentiometers l3 of "No. 1 preset. Since thefader potentiometers ll are u connected in the circuit between thecontrol potentiometers l3 and the proportioning motors l2 in exactly thesame manner as disclosed in Figure 1, movement of the sliders of thefader potentiometers I4 towards the blue causes dimming of the lights ina proportionate manner whereby all of the lights are extinguished atexactly the same time, regardless of their intensities before thisoperation. Likewise, movement. of the sliders of the faderpotentiometers M from the extreme blue position to the midposition shownin the drawings, brightens the lights from an "01? condition to thoseconditions which are determined by the positions of the controlpotentiometers 13 of No. 1 preset. Movement of the sliders of the iaderpotentiometers H from 'the midposition to the extreme white positioncauses proportionate brightening of the lights controlled by theproportioning motors l2 and the lights will be brightened to 100%intensity at exactly the same time. Movement of the sliders of the faderpotentiometers II from the extreme white position to the midpositiondims the lights from 100% brilliancy to that brilliancy' which isdetermined by the position of the control potentiometer [3 of No. lpreset. The specific manner in which this proportionate dimming andbrightening of the lights is accomplished is described in detail inconnection with ,Figure 1.

When the preset switch 205 of No. 2 preset is presets, whereinpresetting of the lights is accomplished, and wherein the lights may beproportionately brightened or dimmed regardless of which preset is incontrol of the proportioning motors I2.

It often occurs, as during rehearsal periods, that it is desirable tochange the intensities of some or the lights while leaving the otherlights at their adjusted values. Specifically, it may be desired tobrighten the "foots but maintain the various border lights at the sameintensities to see what efiect this would have. It is often desired todo this without breaking the preset which is already in control wherebythe two lighting effects may be compared. This mode of operation isaccomplished by the rehearsal potentiometers 208 and the preset releaseswitches 209. Closure of the rehearsal switch 222 connects the whitesand blues of the rehearsal potentiometers 208 to the busses 224 and 225respectively. The blues of the proportioning motors are connected to theblues of the rehearsal potentiometers 208. Movement of the presetrelease switches209 upwardly connects the whites of the rehearsalpotentiometers 208 to the whites of the proportioning motors, and alsobreaks the connection be- .tween the reds of the proportioning motorsand their associated control potentiometers l3. This movement of thepreset release switches 209 also connects the reds of the rehearsalpotentiometers 208 to the reds of the proportioning motors 12. Eachrehearsal potentiometer 208 is provided witha preset release switch 209whereby the control of any proportioning motor l2 may be taken from itsassociated control potentiometer I3 and placed under the control of therehearsal potentiometer 208.

Assume that the preset release switches 209 are all located in the downposition and that the switch. 205 of No. 1 preset" is closed, then theproportioning motors l 2 are positioned in accordance with the positions01 the control potentiometers '13 of that preset. Assume now that thepreset release switch 209 associated with the proportioning motor 12designated facts is moved upwardly, the control of this proportioningmotor is taken away from its control potentiometer l3 and placed underthe control of the rehearsal potentiometer 208. By suitably manipulatingthe associated rehearsal potentiometer 208 the correct lightingintensity controlled by the proportioning motor I 2 designated foots maybe obtained. When this correct lighting intensity is obtained thecontrol poten tiometer, l3 of No. 1 preset" designated .foots may beadjusted to a position corresponding to the position .of the rehearsalpotentiometer 208 designated foots. The preset release switch 209 isthen moved downwardly to the position shown in the drawing and theproportioning motor .12

position corresponding to the newly adjusted position of the controlpotentiometer iii of "No. 1 preset. In a like manner, the proportioningmotors 12 designated No. 1 border" or No. 2 border may be adjusted bymanipulation of the .rehearsal potentiometer 208 associated therewith toarrive at the correct and desired lighting effects.

It ,is therefore seen that in this modification I have not only provideda plurality of control potentiometers arranged in presets for operatingproportioning motors along with means for proportionately dimming orbrightening the lights controlled by the proportioning motors, but Ihave also provided a means whereby the lighting effects controlled bythe proportioning motors l2 may be tested and tried for obtaining-adesired lighting comparison without disturbing any preset in existence.

Referring now to Figure '7, I have shown a means for remotelycontrolling a color wheel associated with a spotlight whereby the colorof the light projected by the spotlight may be remotely controlled. Thespotlights are shown diagrammatically at' 230 and are designated No. 1spotlight, No. 2 spotlight, and "No. 3 spotlight. Each spotlight isprovided with a color wheel 23l which is positioned by a shaft 25operated by a proportioning motor l2. For purposes of illustration it isassumed that the color wheel has amber, red, white, blue and green colorlenses. The proportioning motor l2'is in all respects similar to thatshown in Figure 1 and each proportioning motor is controlled by controlpotentiometer coil, five such taps being shown.

Therefore, the proportioning motor l2 will as- The controlpotentiometers l3 of this designated "foots is caused to remain in this

